High pressure treatment of silicon nitride film

ABSTRACT

Methods and systems relating to processes for treating a silicon nitride film on a workpiece including supporting the workpiece in a chamber, introducing an amine gas into the chamber and establishing a pressure of at least 5 atmospheres, and exposing the silicon nitride film on the workpiece to the amine gas while the pressure in the chamber is at least 5 atmospheres.

TECHNICAL FIELD

This invention concerns high pressure treatment of a silicon nitridelayer on a workpiece such as a semiconductor wafer.

BACKGROUND

Micro-electronic circuits and other micro-scale devices are generallymanufactured by the sequential deposition and patterning of multiplelayers on a substrate or wafer, such as a silicon or other semiconductormaterial wafer. For some applications, an insulating film, e.g., siliconnitride, is deposited on the substrate to form an etch-stop layer, amasking layer, or a gate spacer layer.

For some layers, to achieve desired material properties, the substrateis typically put through an annealing process in which the substrate isquickly heated, usually to about 200-500° C. and more typically to about300-400° C. The substrate may be held at these temperatures for arelatively short time, e.g., 60-300 seconds. The substrate is thenrapidly cooled, with the entire process usually taking only a fewminutes. Annealing may be used to change the material properties of thelayers on the substrate. Annealing may also be used to activate dopants,drive dopants between films on the substrate, change film-to-film orfilm-to-substrate interfaces, densify deposited films, or to repairdamage from ion implantation.

SUMMARY

In one aspect, treating a dielectric film that includes silicon-nitridebonds on a workpiece includes supporting the workpiece that has thedielectric film that includes silicon-nitride bonds in a chamber,introducing an amine gas into the chamber, establishing a pressure of atleast 5 atmospheres in the chamber, and exposing the dielectric filmthat includes silicon-nitride to the anime gas while the pressure in thechamber is at least 5 atmospheres.

Other embodiments of this aspect include corresponding systems,apparatus, and computer programs, configured to perform the actions ofthe methods, encoded on computer storage devices.

These and other embodiments can each optionally include one or more ofthe following features.

A temperature of the dielectric film may be raised to between 200-500°C. The temperature of the silicon nitride film may be raised bymaintaining a support for the workpiece in the chamber at an elevatedtemperature. The temperature of the dielectric film may be raised beforeestablishing the pressure in the chamber of at least 5 atmospheres.

Establishing the pressure in the chamber may include introducing theamine gas in the chamber. In some implementations, the amine gasincludes ammonia gas. The amine gas may include methylamine gas and/ordimethylamine gas. In some implementations, the dielectric film isexposed to the amine gas for at least 5 minutes and no more than anhour.

The dielectric film may be a portion of a fin field-effect transistor(FinFET) in fabrication.

In another aspect, a method of forming a dielectric material on aworkpiece includes depositing a dielectric film that includessilicon-nitride bonds on the workpiece by flowable chemical vapordeposition (FCVD), and exposing the dielectric film that includessilicon-nitride bonds to an amine gas in a chamber while a pressure inthe chamber is at least 5 atmospheres. In some implementations, thedeposition of the dielectric film on the workpiece is at a temperaturebelow 380° C.

In another aspect, an annealing system includes a chamber body thatdefines a chamber, a support to hold a workpiece with an outer surfaceof the workpiece exposed to an environment in the chamber, a robot toinsert the workpiece into the chamber, a gas supply to provide an aminegas to the chamber, a pressure source coupled to the chamber to raise apressure in the chamber to at least 5 atmospheres, and a controllercoupled to the robot, the gas supply and the pressure source. Thecontroller is configured to cause the robot to transport the workpiecehaving a dielectric film on it into the chamber, cause the gas supply tosupply the amine gas to the chamber, and cause the pressure source toraise a pressure in the chamber to at least 5 atmospheres while theworkpiece is held on the support in the chamber.

The annealing system may include a heater to raise a temperature of theworkpiece on the support to between 250-500° C. The heater may include aresistive heater embedded in the support, and/or the heater may be aradiative heater in a wall of the chamber body that is positioned toirradiate the workpiece on the support. The pressure source may includea pump.

Particular embodiments of the subject matter described in thisspecification can be implemented so as to realize one or more of thefollowing advantages. Post-deposition annealing of a silicon nitridefilm can improve film quality, e.g., by strengthening the Si—N—Sinetwork and reducing impurities (e.g., oxygen and carbon) in the siliconnitride film. The use of high pressure amine gas allows for lowertemperature to be used during the anneal process by improving thediffusion of the gas into the silicon nitride layer, maintaining arelatively low thermal budget for the post-processing of the workpieceand preserving overall layer structure quality. Moreover, a relativelylow thermal budget reduces temperature-related effects on otherpre-existing features on the workpiece (e.g., reduced dopant diffusion).Additionally, lower temperatures may be used for depositing the siliconnitride film, thereby reducing intermixing of the silicon nitride layerwith adjacent layers (e.g., tungsten film). The use of high pressure gasmay also have a physical impact in certain applications, e.g., FCVDsilicon nitride gap fill applications, such that the high pressure mayaffect the reflow of the silicon nitride film to achieve improvedvoid-free gap fill in the silicon nitride film.

The details of one or more embodiments of the invention are set forth inthe accompanying drawings and the description below. Other features,objects, and advantages of the invention will be apparent from thedescription and drawings, and from the claims.

DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram of a high-pressure substrate processingsystem.

FIG. 2 is a flow diagram of an example process flow for annealing asilicon nitride film by high pressure treatment in a high-pressuresubstrate processing system.

FIG. 3 depicts an example high-pressure substrate processing system.

FIG. 4 depicts another example of a high-pressure substrate processingsystem.

Like reference symbols in the various drawings indicate like elements.

DETAILED DESCRIPTION

In general, it is desirable to improve film quality of layers depositedon a workpiece, e.g., a deposited silicon nitride film on asemiconductor wafer. For example, a silicon nitride film deposited on asemiconductor wafer can be used in a patterning process for fabricationof a fin field-effect transistor (FinFET). Poor film quality may arisein a variety of manners; without being limited to any particular theory,poor film quality can result from impurities during the depositionprocess. For example, using particular deposition chemistries to depositthe silicon nitride film may result in defects in the silicon nitridefilm due to Si—H and N—H bonding. In some implementations, defects arisein the silicon nitride film due to Si—C and C—N bonds. Additionally,after the silicon nitride film is exposed to air, some defects may beconverted to Si—O bonds. Physical pinholes and/or voids may also bepresent in deposited silicon nitride films, causing poor film quality.

Poor film quality in silicon nitride film may also result fromincomplete formation of a Si—N—Si network during the deposition processof the silicon nitride layer. For example, the high temperatures used todeposit the silicon nitride film results in intermixing of the siliconnitride film with surrounding layers (e.g., tungsten). To mitigateintermixing of the silicon nitride film and adjacent layers (e.g.,tungsten), lower deposition temperatures are used for depositing thesilicon nitride film, which results in lower film quality.

Described below are systems and methods for high pressure treatment toimprove silicon nitride film quality using a high pressure anneal. Asilicon nitride film deposited on a workpiece is exposed to highpressure (e.g., at least 5 atmospheres) of amine gas (e.g., ammonia gas)while held at elevated temperatures (e.g., 200-500° C.) for a fewminutes to an hour. Again without being limited to any particulartheory, the high pressure treatment described herein can be effective inreducing dangling Si and N bonds as well as reducing contamination(e.g., Si—C bonds) resulting from the deposition process in the siliconnitride layer. The high pressure treatment can also be effective inconverting Si—H bonds and Si—O bonds to Si—N bonds, and furthermore maybe effective in breaking N—H bonds as well. This can reduce detrimentaleffects such as uneven etch rates and/or high etch rates of the siliconnitride layer and decreased leakage in silicon nitride gate spacers inFinFET devices.

System

FIG. 1 is a block diagram of a high-pressure substrate processing system100. The high-pressure substrate processing system 100 includes a highpressure chamber 102. The high pressure chamber 102 is configured tocontain pressures of at least 5 atmospheres, e.g., at least 10atmospheres, and can be capable of holding vacuum levels of up to 10∧-3Torr when under vacuum. In some implementations, the high-pressuresubstrate processing system 100 includes a low-pressure environment 104,e.g., a vacuum chamber, for when a workpiece is being transferredbetween processing chambers (e.g., from another processing chamber intothe high pressure chamber 102). The relative pressures within the highpressure chamber 102 and the low pressure chamber 104 can be controlledindependently of each other.

A robot (not depicted in FIG. 1) including a robotic arm can be used totransfer the workpiece into and out of the high pressure chamber 102,e.g., between the chambers of a multi-chamber substrate processing tool.

The high pressure chamber 102 includes a support, for example, pedestal106 for supporting a workpiece in the high pressure chamber 102. Thepedestal 106 supports one or more workpieces using a variety of supportmechanisms, for example, the pedestal 106 may support the workpiece withlocking pins and springs, and/or the workpiece may rest directly on topof the pedestal 106.

In some implementations, the high pressure chamber 102 includes one ormore heating elements 108. For example, heating element 108 a is aresistive heater and is integrated into the pedestal 106 for heating theworkpiece. In some implementations, the high pressure chamber 102includes a heating element 108 b, where the heating element 108 b canheat and maintain a selected temperature within the high pressurechamber 102. Heating element 108 b may be a radiative heater embedded ina wall of the high pressure chamber body, and positioned to irradiatethe workpiece on the pedestal 106. The heat from the heating elements108 can be sufficient to anneal the workpiece when the workpiece issupported on the pedestal 106 and a gas (if used) has been introducedinto the high pressure chamber 102. The heating elements 108 may beresistive heating elements, and may heat the workpiece conductivelyand/or radiatively. Additionally, the heating elements 108 may include adiscrete heating coil, or a radiative heater (e.g., an infrared lamp).

A gas delivery system 110 is operable to pressurize and depressurize thehigh pressure chamber 102. The gas delivery system 110 provides a gasmixture to the high pressure chamber 102 to establish a high pressure,e.g., a pressure of at least 5 atmospheres. In some implementations, thegas delivery system 110 includes an exhaust system 112 to exhaust thegas from the high pressure chamber 102 thereby depressurizing the highpressure chamber 102. The gas delivery system includes a pressure sourceto raise the pressure in the chamber 102 to the high pressure. Thepressure source can include a pump, e.g., a rotary pump, a scroll pump,or a screw pump, configured to pump gas into the chamber 102 until thedesired pressure is reached, and/or a compressed gas cylinder at apressure sufficient that, after the gas cylinder is fluidicallyconnected to the chamber 102, the equalized pressure will reach thedesired pressure.

A pumping system 114 includes one or more pumps for reducing pressuresin the high pressure chamber 102 and/or the vacuum chamber 104. Pumpsmay include one or more rotary pumps, scroll pumps, and screw pumps. Forexample, the pumping system 114 can be used to lower the pressure in thevacuum chamber 104 to be at vacuum or near-vacuum pressure, e.g., lessthan 1 milliTorr. In another example, the pumping system 114 may be usedduring a pump and purge cycle in the high pressure chamber 102 to reducepresence of contaminants in the high pressure chamber 102 prior toprocess operation.

In some implementations, a valve assembly 116 isolates the relativepressures between the high pressure chamber 102 and the vacuum chamber104. The high-pressure environment within the high pressure chamber 102can thus be separated and sealed from the low pressure environmentwithin the vacuum chamber 104. The valve assembly 116 is operable toenable the workpiece to be transferred directly between the highpressure chamber 102 and the vacuum chamber 104.

In some implementations, the high-pressure substrate processing system100 includes a foreline 118 connected to the vacuum chamber 104 andconnected to an outside environment. An isolation valve 120 is arrangedalong the foreline 118 to isolate the pressure within the vacuum chamber104 from the pressure of the outside environment. The isolation valve120 can be operated to adjust the pressure within the vacuum chamber 104and to releases gases within the vacuum chamber 104. The isolation valve120 can be operated in conjunction with the pumping system 114 toregulate the pressure within the vacuum chamber 104.

One or more operations of the high-pressure substrate processing system100 may be controlled by one or more controllers 122. The controller122, e.g., a general purpose programmable computer, is connected to andoperable to control some or all of the various components of thehigh-pressure substrate processing system 100. Operations controlled bycontroller 122 may include, for example, temperature regulation of theheating elements 108 within the high pressure chamber 102, pressureregulation within the high pressure chamber 102, vacuum regulationwithin the vacuum chamber 104, flow rates and gas delivery by the gasdelivery system 110, and operation of one or more pumps in the pumpingsystem 114. For example, the controller 122 can be programmed togenerate control signals that cause the components of the high-pressuresubstrate processing system 100 to carry out the process described belowwith reference to FIG. 2.

High-Pressure Treatment of a Silicon Nitride Film

FIG. 2 is a flow diagram of an example process flow 200 forhigh-pressure annealing of a silicon nitride film on a workpiece in ahigh-pressure substrate processing system 100. In one example, aworkpiece includes a semiconductor substrate (e.g., silicon), with asilicon nitride film deposited on the substrate. In someimplementations, the silicon nitride film forms part of a fin fieldeffect transistor (FinFET) structure fabricated on the substrate; theworkpiece may also include layers of other materials (e.g., TiN,tungsten). The silicon nitride film may be deposited on the workpieceusing flowable chemical vapor deposition (FCVD) in a separate processingstep. In some implementations, plasma-etched chemical vapor deposition(PECVD), low pressure chemical vapor deposition (LPCVD), and/or atomiclayer deposition (ALD) may be utilized to deposit the silicon nitridefilm.

The workpiece is inserted into the chamber, e.g., by the robot, and thensupported in the chamber, e.g., on a pedestal 106 within the highpressure chamber 102 (202). In some implementations, the high pressurechamber 102 and/or the pedestal 106 are maintained at a particulartemperature (e.g., 200-500° C.) using one or more heating elements 108.The temperature of the high pressure chamber 102 and/or the pedestal 106may be established prior to introducing the workpiece into the highpressure chamber 102. Furthermore, the temperature of the workpiece(e.g., a silicon nitride film on a substrate) may be established at aparticular temperature (e.g., 200-600° C.) through the use of one ormore heating elements 108 while the workpiece is supported by thepedestal 106 in the high pressure chamber 102. In some implementations,the temperature of the workpiece (e.g., the silicon nitride film on thesubstrate) is raised prior to establishing the pressure in the highpressure chamber 102 of at least 5 atmospheres.

An amine gas is introduced into the high pressure chamber 102 (204). Theamine gas can be ammonia gas or another small and reactive amine gas(e.g., methylamine gas or dimethylamine gas). In some implementations,multiple different amine gases (e.g., ammonia gas and methylamine gas)may be mixed into a gas mixture before being delivered into the highpressure chamber 102 by the gas delivery system 110, or the multipledifferent amine gases (e.g., ammonia gas and methylamine gas) can bedelivered into the high pressure chamber 102 by separate nozzles of thegas delivery system 110, and mixed in the high pressure chamber 102. Insome implementations, the amine gas may be mixed with an inert gas(e.g., nitrogen, argon, or helium) prior to being delivered into thehigh pressure chamber 102 by the gas delivery system 110, for example,to reduce flammability of the gas mixture.

The gas delivery system 110 can establish a total pressure of 5 to 50atmospheres in the high pressure chamber 102 (206). In someimplementations, the total pressure in the high pressure chamber is atleast 10 atmospheres. The total pressure of amine gas in the highpressure chamber 102 may be established as a static pressure in thechamber, or may be established through a flow of amine gas in and out ofthe chamber during the annealing process. The total pressure of 5 to 50atmospheres can be provided by the amine gas. For example, the gasintroduced into the high pressure chamber can consist of amine gas,i.e., only amine gas is introduced into the high pressure chamber.

After the desired pressured is established in the high pressure chamber102, the silicon nitride film on the workpiece is exposed to the aminegas while the high pressure chamber 102 is maintained at the elevatedpressure (208). Exposure times include a few minutes to several hours(e.g., at least 5 minutes, and no more than one hour). In someimplementations, the annealing temperature (e.g., temperature of theworkpiece during the anneal process), the amine gas pressure in the highpressure chamber 102, and exposure times for the high-pressure annealingprocess, may be interrelated such that optimal operational parametersmay be found by adjusting the aforementioned (and other) variables.

Without being limited to any particular theory, the high pressure aminegas treatment can be effective in converting Si—H bonds and Si—O bondsto Si—N bonds, and furthermore may be effective in breaking N—H bondswhich will enable the formation of Si—N bonds in the silicon nitridefilm.

In some implementations, the amine gas is introduced into the highpressure chamber 102 by the gas delivery system prior to or during theheating process of the workpiece. For example, a high pressure of aminegas (e.g., ammonia gas) may be introduced into the high pressure chamber102 while heating elements 108 are bringing a workpiece on a pedestal106 to a particular desired temperature.

In some implementations, the workpiece may be heated to a particulartemperature while it is in the vacuum chamber 104 and then subsequentlytransferred to the high pressure chamber 102 by a robot (not depicted),where the amine gas (e.g., ammonia gas) may be introduced.

In some implementations, a silicon nitride film is deposited on aworkpiece, which may then undergo the high pressure treatment describedherein. For example, a silicon nitride film can be deposited on theworkpiece by flowable chemical vapor deposition (FCVD) using a gascomposition of, e.g., trisilylamine/silane/ammonia. Due to a lower(e.g., below 380° C.) deposition temperature for the silicon nitridefilm, lower film quality may result. The silicon nitride film may thenbe exposed to an amine gas in a high pressure chamber 102 while apressure in the high pressure chamber 102 is at least 5 atmospheres. Insome implementations, the silicon nitride film is used as an etchhard-mask, such that a process to etch trenches in the silicon nitridelayer may be performed on the silicon nitride layer (e.g., using aplasma gas composition such as a SF6/CH4/N2/O2 plasma) before and/orafter the high pressure treatment of the silicon nitride layer on theworkpiece.

Embodiments of High-Pressure Substrate Processing Systems

FIGS. 3 and 4 depict two embodiments of high-pressure substrateprocessing systems. FIG. 3 depicts an example high-pressure substrateprocessing system 300 including a first chamber 302 (e.g., a highpressure chamber 102), a pedestal 304, a second chamber 306 (e.g., avacuum chamber 104), and a controller (e.g., the controller 122). Thehigh-pressure substrate processing system 300 further includes a pumpingsystem (not shown) similar to the pumping system 114 and a gas deliverysystem 307 similar to the gas delivery system 110 described with respectto FIG. 1. For example, the gas delivery system 307 includes an inputline 307 a and an exhaust line 307 b. The amine gas is introduced intothe first chamber 302 through the input line 307 a, and the amine gas isexhausted from the first chamber 302 through the exhaust line 307 b.

The pedestal 304 supports a workpiece (i.e., substrate) 314 on which afilm of material (e.g., silicon nitride film) is to be processed througha high pressure treatment. The pedestal 304 is positioned orpositionable within the first chamber 302. In some implementations, thesubstrate 314 sits directly on a flat top surface of the pedestal. Insome implementations, the substrate 314 sits on pins 330 that projectfrom the pedestal.

The high-pressure substrate processing system 300 includes an inner wall320, a base 322, and an outer wall 324. The first chamber 302 isprovided by a volume within the inner wall 320, e.g., between the innerwall 320 and the base 322. The second chamber 306 is provided by avolume outside the inner wall 320, e.g., between the inner wall 320 andthe outer wall 324.

The high-pressure substrate processing system 300 further includes avalve assembly 316 between the first chamber 302 and the second chamber306 that provides the functionality of the valve assembly 116 of FIG. 1,i.e., it can be operated to isolate the first chamber 302 from thesecond chamber 306. For example, the valve assembly 316 includes theinner wall 320, the base 322, and an actuator 323 to move the base 322relative to the inner wall 320. The actuator 323 can be controlled todrive the base 322 to move vertically, e.g., away from or toward thewalls 320 defining the first chamber 302. A bellows 328 can be used toseal the second chamber 306 from the external atmosphere whilepermitting the base 322 to move vertically. The bellows 328 can extendfrom a bottom of the base 322 to a floor of the second chamber 306formed by the outer wall 324.

When the valve assembly 316 is in a closed position, the base 322contacts the walls 320 such that a seal is formed between the base 322and the walls 320, thus separating the second chamber 306 from the firstchamber 302. The actuator 323 is operated to drive the base 322 towardthe inner walls 320 with sufficient force to form the seal. The sealinhibits air from the first high-pressure chamber 302 from beingexhausted into the low-pressure second chamber 306.

When the valve assembly 316 is in an open position, the base 322 isspaced apart from the walls 320, thereby allowing air to be conductedbetween the first and second chambers 302, 306 and also allowing thesubstrate 314 to be accessed and transferred to another chamber.

Because the pedestal 304 is supported on the base 322, the pedestal 304is thus also movable relative to the inner walls 320. The pedestal 304can be moved to enable the substrate 314 to be more easily accessible bythe transfer robot. For example, an arm of a transfer robot (notdepicted) can extend through an aperture 326 in the outer wall 324. Whenthe valve assembly 316 is in the open position, the robot arm can passthrough the gap between the inner wall 320 and the base 322 to accessthe substrate 314.

In some implementations, the high-pressure substrate processing system300 includes one or more heating elements 318 configured to apply heatto the substrate 314. The heat from the heating elements 318 can besufficient to anneal the substrate 314 when the substrate 314 issupported on the pedestal 304 and the precursor gas (if used) has beenintroduced into the first chamber 302. The heating elements 318 may beresistive heating elements. The one or more heating elements 318 may bepositioned in, e.g., embedded in, the inner walls 320 defining the firstchamber 302. This heats the inner wall 320, causing radiative heat toreach the substrate 314. The substrate 314 can be held by the pedestal304 in close proximity to the ceiling of inner wall to improvetransmission of heat from the inner wall 320 to the substrate 314.

However, the one or more heating elements 318 may be arranged in otherlocations within the high-pressure substrate processing system 300,e.g., within the side walls rather than ceiling. An example of a heatingelement 318 includes a discrete heating coil. Instead of or in additionto a heater embedded in the inner walls 320, a radiative heater, e.g.,an infrared lamp, can be positioned outside the first chamber 302 anddirect infrared radiation through a window in the inner wall 320.Electrical wires connect an electrical source (not shown), such as avoltage source, to the heating element, and can connect the one or moreheating elements 318 to the controller.

The controller is operably connected to the pumping system, the gasdelivery system 307, and the valve assembly 316 for controllingoperations to perform the high pressure treatment of a layer of materialon the substrate 314. In some implementations, the controller may alsobe operably connected to other systems. For example, the controller canalso be operably connected to one or more of the transfer robots (notdepicted), the one or more heating elements 318, and/or the actuator323. In some cases, the controller 122 shown in FIG. 1 includes thecontroller of the high-pressure substrate processing system 300.

In a process to perform a high pressure treatment of a layer of materialon the substrate 314, the controller can operate the pumping system todepressurize the second chamber 306 to a low-pressure state, e.g., to astate in which the second chamber 306 has a pressure less than 1atmosphere, to prepare for transfer of the substrate 314 through thesecond chamber 306. The low-pressure state can be a near-vacuum state,e.g., a pressure less than 1 milliTorr. The substrate 314 is movedthrough the second chamber 306 by a transfer robot (not shown), whilethe second chamber 306 is at the low-pressure so that contamination andoxidation of the substrate 314 can be inhibited.

The substrate 314 is transferred into the first chamber 302 forprocessing. To transfer the substrate 314 into the first chamber 302,the controller can operate the valve assembly 316, e.g., open the valveassembly 316 to provide an opening through which the substrate 314 canbe transferred into the first chamber 302. The controller can operatethe transfer robot to carry the substrate 314 into the first chamber 302and to place the substrate 314 on the pedestal 304.

After the substrate 314 is transferred into the first chamber 302, thecontroller can operate the valve assembly 316 to close the opening,e.g., close the valve assembly 316, thereby isolating the first andsecond chambers 302, 306 from one another. With the valve assembly 316closed, pressures in the first chamber 302 and the second chamber 306can be set to different values. The controller can operate the gasdelivery system 307 to introduce the amine gas into the first chamber302 to pressurize the first chamber 302. The introduction of the aminegas can increase the pressure within the first chamber 302, for example,to 5 atmospheres or more.

The amine gas and the proper temperature and pressure conditions in thefirst chamber 302 can cause the high pressure treatment of the materialto occur, e.g., as described with reference to FIG. 2. During the highpressure treatment, the controller can operate the one or more heatingelements 318 to add heat to the substrate 314 to facilitate theannealing of the layer of material on the substrate 314.

When the high pressure treatment is complete, the substrate 314 can beremoved from the first chamber 302 using the transfer robot and, ifnecessary, the substrate 314 can be transferred to a subsequent processchamber or to the outside environment. Alternatively, the substrate 314is transferred into a load lock chamber (not shown). To prepare fortransfer of the substrate 314 out of the first chamber 302, thecontroller can operate the exhaust system of the gas delivery system 307to depressurize the first chamber 302 before the valve assembly 316 isopened. In particular, before the substrate 314 is transferred out ofthe first chamber 202, the precursor gas is exhausted from the firstchamber 302 to reduce the pressure within the first chamber 202. Thepressure in the first chamber 302 can be reduced to a near-vacuumpressure such that the pressure differential between the first chamber302 and the second chamber 306 can be minimized.

To enable the substrate 314 to be transferred out of the first chamber302, the controller can open the valve assembly 316. The opened valveassembly 316 provides an opening through which the substrate 314 ismoved to be transferred into the second chamber 306. In particular, theopened valve assembly 316 enables the substrate 314 to be transferreddirectly into the second chamber 306, e.g., into the low pressureenvironment of the second chamber 306.

FIG. 4 depicts another example of a high-pressure substrate processingsystem 400 including a first chamber 402 (e.g., high pressure chamber102), a pedestal 404, a second chamber 406 (e.g., vacuum chamber 104),and a controller similar to controller 122 shown in FIG. 1. Thehigh-pressure substrate processing system 400 is similar to thehigh-pressure substrate processing system 300 described with respect toFIG. 3; unless otherwise specified the various options andimplementations are also applicable to this embodiment.

For example, the gas delivery system and the pumping system of thehigh-pressure substrate processing system 400 are operated in a similarmanner to maintain the low and high pressure environments for asubstrate 414 processed using the high-pressure substrate processingsystem 400. The second chamber 406 can be defined by volume betweeninner walls 420 and outer walls 424. In addition, the substrate 414 isalso supportable on the pedestal 404 for processing within the firstchamber 402. Again, the substrate can sit directly on the pedestal 404,or sit on lift pins 430 that extend through the pedestal.

The high-pressure substrate processing system 400 differs from thehigh-pressure substrate processing system 300 of FIG. 3 in a fewregards. First, inner walls 420 defining the first chamber 402 are notmovable relative to a base 422 defining the first chamber 402. Thepedestal 404 is thus fixed relative to the inner walls 420 and the base422. In some examples, the pedestal 404 is fixed to the base 422defining the first chamber 402.

Rather than being arranged in the inner walls 420 of the first chamber402, as is the case for the one or more heating elements 318 of theembodiment of FIG. 3, one or more heating elements 418 of the embodimentdepicted in FIG. 4 are arranged within the pedestal 404. The substrate414 is thus heated through contact with the pedestal 404.

The high-pressure substrate processing system 400 further includes avalve assembly 416 between the first chamber 402 and the second chamber406 that, similar to the valve assembly 316 of FIG. 3, isolates thefirst chamber 402 from the second chamber 406. However, in contrast tothe valve assembly 316, the valve assembly 416 is not formed by thewalls 420 and the base 422 defining the first chamber 402, but rather isformed by an arm 425 movable relative to the inner walls 420 and thebase 422 of the first chamber 402. The arm 425 may be movable relativeto the inner walls 420 and the base 422 of the first chamber 402.

In particular, the valve assembly 416 includes a slit valve 423 betweenthe first chamber 402 and the second chamber 406. The slit valve 423includes a slit 423 a and the arm 425. The slit 423 a extends throughone of the inner walls 420 of the first chamber 402. A proximal end 425a of the arm 425 is positioned outside of the first chamber 402 while adistal end 425 b of the arm 425 is positioned within the first chamber402. The proximal end 425 a of the arm 425 can be positioned within thesecond chamber 406 and be driven by an actuator positioned within thesecond chamber 406. Alternatively, the proximal end 425 a of the arm 425is positioned outside of the second chamber 406 and is thus driven by anactuator 428 that is also positioned outside of the second chamber 406.

The arm 425 extends through the slit 423 a and is movable relative tothe walls 420 so that the arm 425 can be moved to a position in which itforms a seal with the walls 420. The actuator 428 is coupled to theproximal end 425 a of the arm 425 and drives the distal end 425 b of thearm 425 relative to the walls 420. The arm 425 is also movablevertically to cover or uncover the slit 423 a. In particular, theproximal end 425 a of the arm 425 can be or include a flange thatextends substantially parallel to the adjacent inner surface of theinner wall 420. The arm 425 is also movable and driven laterally so thatthe distal end 425 b of the arm 425 can engage or disengage the innerwalls 420.

The arm 425 can also extend through an aperture (e.g., slit) 426 in theouter wall 424.

Like the valve assembly 316, the valve assembly 416 is movable betweenan open position and a closed position. When the valve assembly 416 isin the closed position, the distal end 425 b of the arm 425 covers theslit 426 and contacts one of the inner walls 420, thereby forming theseal to isolate the first chamber 402 from the second chamber 406. Inparticular, the distal end 425 b of the arm 425, e.g., the flange,contacts an inner surface of the wall 420 defining the first chamber402.

When the valve assembly 416 is in the open position, the distal end 425b of the arm 425 is spaced laterally apart from the inner walls 420,e.g., the inner surface of the inner walls 420. In addition, the distalend 425 b of the arm 425 is positioned vertically so that the slit 426is uncovered. The slit 426 thus provides an opening that enables fluidiccommunication between the first chamber 402 and the second chamber 406and that also enables the substrate 414 to be moved in and out of thefirst chamber 402, e.g., by a robot as discussed above.

The controller can operate the high-pressure substrate processing system400 in a manner similar to the process described with respect to thecontroller of the high-pressure substrate processing system 300 totransfer the substrate 414 into and out of the first chamber 402 and toperform the high pressure treatment on the layer of material on thesubstrate 414. In this process, to open and close the valve assembly416, the controller can operate the actuator 428 to drive the arm 425.

An advantage of the configuration shown in FIG. 4 is that the pressurewithin the first chamber 402 helps force the distal end 425 b of the arm425 against the inner surface of the inner wall 420. Consequently, incontrast to the configuration shown in FIG. 3, the actuator can be lesspowerful.

The controller and other computing devices part of systems describedherein can be implemented in digital electronic circuitry, or incomputer software, firmware, or hardware. For example, the controllercan include a processor to execute a computer program as stored in acomputer program product, e.g., in a non-transitory machine readablestorage medium. Such a computer program (also known as a program,software, software application, or code) can be written in any form ofprogramming language, including compiled or interpreted languages, andit can be deployed in any form, including as a standalone program or asa module, component, subroutine, or other unit suitable for use in acomputing environment.

While this document contains many specific implementation details, theseshould not be construed as limitations on the scope of any inventions orof what may be claimed, but rather as descriptions of features specificto particular embodiments of particular inventions. Certain featuresthat are described in this document in the context of separateembodiments can also be implemented in combination in a singleembodiment. Conversely, various features that are described in thecontext of a single embodiment can also be implemented in multipleembodiments separately or in any suitable subcombination. Moreover,although features may be described above as acting in certaincombinations and even initially claimed as such, one or more featuresfrom a claimed combination can in some cases be excised from thecombination, and the claimed combination may be directed to asubcombination or variation of a subcombination.

Although the discussion above has focused on silicon nitride, otherdielectric films that include silicon-nitride bonds, e.g., siliconoxynitride (SiON) or silicon carbon nitride (SiCN), may be deposited,e.g., by a low temperature or FCVD process, and treated using the highpressure treatment described herein.

Accordingly, other embodiments are within the scope of the followingclaims.

What is claimed is:
 1. A method of thermally annealing a dielectric filmthat includes silicon-nitride bonds on a workpiece, comprising:supporting the workpiece that has the dielectric film that includessilicon-nitride bonds in a chamber; raising a temperature of thedielectric film to between 200-500° C. before introducingneutrally-charged amine gas into the chamber; establishing a pressure ofat least 5 atmospheres in the chamber; and exposing the dielectric filmon the workpiece to the neutrally-charged amine gas at the raisedtemperature while the pressure in the chamber is at least 5 atmospheresto thermally anneal the dielectric film.
 2. The method of claim 1,wherein raising the temperature of the dielectric film comprisesmaintaining a support for the workpiece in the chamber at an elevatedtemperature.
 3. The method of claim 1, wherein establishing the pressurein the chamber comprises introducing the neutrally-charged amine gas inthe chamber.
 4. The method of claim 3, wherein the neutrally-chargedamine gas comprises ammonia gas.
 5. The method of claim 3, wherein theneutrally-charged amine gas includes methylamine gas and/ordimethylamine gas.
 6. The method of claim 1, wherein the dielectric filmis a portion of a fin field-effect transistor in fabrication.
 7. Themethod of claim 1, comprising exposing the dielectric film to theneutrally-charged amine gas for at least 5 minutes.
 8. The method ofclaim 1, wherein the dielectric film is a silicon nitride, siliconoxynitride or silicon carbon nitride film.
 9. The method of claim 1,wherein the pressure is at least 10 atmospheres.
 10. A method of formingand thermally annealing a dielectric material on a workpiece,comprising: depositing a dielectric film that includes silicon-nitridebonds on the workpiece by flowable chemical vapor deposition; raising atemperature of the dielectric film to between 200-500° C. beforeintroducing neutrally-charged amine gas; and exposing the dielectricfilm that includes silicon-nitride bonds on the workpiece to theneutrally-charged amine gas in a chamber while a pressure in the chamberat the raised temperature is at least 5 atmospheres to thermally annealthe dielectric film.
 11. The method of claim 10, wherein the depositionof the dielectric film on the workpiece is at a temperature below 380°C.
 12. The method of claim 10, comprising establishing the pressure inthe chamber by introducing the neutrally-charged amine gas in thechamber.
 13. The method of claim 12, wherein the neutrally-charged aminegas is ammonia gas.
 14. The method of claim 10, wherein the dielectricfilm is a portion of a fin field-effect transistor.
 15. The method ofclaim 10, wherein the dielectric film is a silicon nitride, siliconoxynitride or silicon carbon-nitride film.
 16. A method of thermallyannealing a dielectric film that includes silicon-nitride bonds on aworkpiece, comprising: supporting the workpiece having the dielectricfilm that includes silicon-nitride bonds in a chamber; raising atemperature of the dielectric film to between about 200-500° C. prior tointroducing neutrally-charged amine gas into the chamber; establishing atotal pressure of at least 5 atmospheres in the chamber, wherein thetotal pressure is provided by the neutrally-charged amine gas; andexposing the dielectric film on the workpiece to the neutrally-chargedamine gas at the raised temperature while the total pressure in thechamber is at least 5 atmospheres to thermally anneal the dielectricfilm.
 17. The method of claim 16, wherein the total pressure is at least10 atmospheres in the chamber.